Nitrox / Calculator 01
EANx Best Mix Calculator
Calculate the highest oxygen percentage for a planned maximum depth and chosen oxygen partial-pressure limit.
The numbers / explained
Ready when you are.
Start with the example or enter your own numbers, then calculate.
Every result includes units. All calculations run in your browser.
01 / The calculation
How it works
Oxygen fraction = PO₂ limit ÷ (depth ÷ 33 + 1), using feet; replace 33 with 10 for meters. The whole-percent mix is rounded down so rounding does not exceed the chosen limit.
Reference: NOAA diving formulas02 / Before you use it
Keep in mind
Sea-level seawater approximation. This is an oxygen depth limit, not a gas-blending recipe. Analyze the actual cylinder, confirm its MOD and account for depth variation and exposure time. A computed mix below 21% is outside this air/nitrox tool's scope.